Another trick is to insert the scandoubler first, then cut the faceplate at the lower end of the scandoubler port, then insert the CV3D into the zorro slot, then put the lil cable that connects the cards... Done!
Sure it might not be 100% pritty but it's a choise between hours of work in which unusual amount of force is used to fit it vs a very simple fitting like almost any other card and then only have 3/4 of the faceplate at the back.
A much harder work is to remove/fit those darn video cards with millions of round connectors sticking out the back... have to remove all cards, loosen the screws for the reiser board, then pull the zorro card out of the slot, then gently bend the hole case till the zorro card can be pushed down/upp and out of the slide on the back, continue till the connectors on the back of the card is inside the casing and take out the card at an angle... lovley. :-D